I wish I were as diligent or clean as you were. Sadly, I don't have anything as rigorous as what you've done. I don't even think I took any pictures. I recall doing the following:
Do you have any pics or a thread showing your modifications?
- First off, I had already flipped my axle housing around, which put the tie rod in the front. I had done this when I built this vehicle, to put the pinion in the right place (passenger side of centerline) to engage the M35 transfer case, which I retained. Turning the whole axle around was far easier than pulling the hubs, then the shafts, and turning around the centersection, which also involves redrilling some mounting holes in the centersection. I have done that on M35 axles to relocate the pinion, and it is a bit onerous. Furthermore, I think I also achieved better pinion location by doing this "lazy" method, based on offset of the axle housing's banjo.
- Redrilling the brake spiders. The goal there was to locate the S-cam camshaft in the absolute "lowest" place in the knuckle, which happens to be just next to the top kingpin. I mean "lowest" not in terms of vertical height, but rather in terms of radial distance from axle centerline. Achieving that goal required that I drill a new series of holes out of phase. This pattern was easy to mark by using the spindle as a template, along with transfer punches to transfer the marks. I drilled these holes (in the 1/2+" thick casting!) using my mag-drill, which drills holes on par with reamed bores.
- Very light grinding / surfacing of that "low point" on the knuckle, where the camshaft passes, by no more than 1/8" or so. This helped clear that camshaft guide.
- Cutting and rewelding of the camshaft mount, to reclock the slack adjuster in a better location. This camshaft guide is already a fabricated part, which I rewelded with proper technique.
- Slightly notching the casting web on the steering knuckles (between main body and the tie rod mounting point) to clear the drums. Alternately, I could have turned down the drums, but my lathe only goes to 13" and I didn't yet have a mill. As another potential solution, I could have also spaced out the whole works.
In all, not a ton of compromises. I will try to take some pics later. Obviously, the internal stuff will be impossible to photograph from afar.
I got these brakes as part of a package deal. I scrapped the axles, with brakes, off an M54 that (decades ago) had the rear axles converted to air using an older system, with the front not wearing any brakes, acceptable as it was pre-'64 (or whatever the cut-off was for no front brakes on OTR trucks, can't remember). I believe the system was configured and sold by Memphis Equipment, but that was based on hearsay. And, having never compared 5 ton stock drums vs. these, I cannot be sure if these are matched to the spiders or if this is a creative reuse of stock drums, but I strongly suspect the former.
I bought all three axles, figuring that the commonality in the axle platform should allow me to take the brakes off one of the rear and put it on the front. Luckily, I was correct, even if it took some work.
I tied these into the existing air brake system for a 1994 Ford C8000 chassis, which lent the frame, engine, and air brake system to this most recent build.
As you know, the 16.5x7 brakes were (from memory) designed for a GVWR of up to 80k lbs. On a truck that weighs 15k, a heavy braking foot plus those systems will help you kiss the windshield.